Abstract: A system for monitoring an ECG during an MRI examination which permits the monitoring system to be located near the patient and which eliminates artifacts affecting the accurate reading of the ECG. The system allows for control of lead select and battery on stand by mode and can monitor battery state and lead off conditions.

Abstract: An electrodynamic loudspeaker for use in a magnetic field generated by an external source, the speaker comprising an acoustic diaphragm attachable to a non-magnetic speaker frame at one end thereof; and a voice coil wound on a bobbin attached to the opposite end thereof, the speaker frame being adapted for mounting the speaker within the external field, the speaker further comprising a magnetic field diverter for locally reshaping the external field in the area of the voice coil for improved efficiency, and including provisions for effectuating operation of the speaker in external fields which may be oriented at various angles relative to the longitudinal extent of the diaphragm.

Abstract: An optical sensor system (such as an oximeter system) for use on a patient in an electrical environment (such as an RF field) includes at least one of the following three subsystems: (A) A light input subsystem includes a first control and display module disposed remotely outside of an electrical field, and input electrical cable connected at one end to the first module and at the other end to an electrically-powered light source disposed closely adjacent but outside of the electrical field. Input fiber optic cable for the transmission of analog optical signals extends from the light source to adjacent a patient in the electrical field. (B) A light output subsystem includes output fiber optic cable for the transmission of analog optical signals extending from adjacent the patient in the electrical field to a light detector disposed closely adjacent but outside of the electrical field.